TY - JOUR
T1 - A nitrogen-doped mesopore-dominated carbon electrode allied with anti-freezing EMIBF4-GBL electrolyte for superior low-temperature supercapacitors
AU - Li, Jing
AU - Zhou, Yanan
AU - Tian, Jiarui
AU - Peng, Lele
AU - Deng, Jie
AU - Wang, Ning
AU - Qian, Weizhong
AU - Chu, Wei
N1 - KAUST Repository Item: Exported on 2020-10-01
Acknowledgements: This work was supported by the National Natural Science Foundation of China (21506111). The authors also gratefully acknowledge the help of Z. Z. Ye, J. Wang, Z. F. Yang, and K.Chao. The author Jing Li thanks for the Financial support from China Scholarship Council (CSC, File No. 201806240341).
PY - 2020/4/29
Y1 - 2020/4/29
N2 - Ionic liquids (ILs) show great promise to endow electric double-layer capacitors (EDLCs) with high energy density; however, their operation in practical deep-cold environments has been severely plagued by two major problems, namely (i) poor compatibility between the electrode material and the ILs and (ii) the ease of freezing of ILs. Here, we show that the combination of a nitrogen-doped mesopore-dominated hierarchical carbon (NMHC) electrode with plentiful ion-accessible adsorption sites (specific surface area and pore volume of 2637.4 m2 g-1 and 1.679 cm3 g-1) and anti-freezing EMIBF4-GBL electrolyte with high ion-conductivity (2.3 S cm-1 at -50 °C) can address this issue. Specifically, "H-bond breakage" in EMIBF4 ILs was proposed for the first time to understand the anti-freezing mechanism, as evidenced by Raman spectroscopy, 1H NMR spectroscopy, and density functional theory calculations. As a result, the combination of NMHC electrode with EMIBF4-GBL electrolyte enabled an impressive specific energy of 61 W h kg-1 at -50 °C, which was 10.7 times larger than that of commercial YP50. This work showed excellent electrode-electrolyte synergy and provides a new understanding of IL-based electrolytes for low-temperature energy storage.
AB - Ionic liquids (ILs) show great promise to endow electric double-layer capacitors (EDLCs) with high energy density; however, their operation in practical deep-cold environments has been severely plagued by two major problems, namely (i) poor compatibility between the electrode material and the ILs and (ii) the ease of freezing of ILs. Here, we show that the combination of a nitrogen-doped mesopore-dominated hierarchical carbon (NMHC) electrode with plentiful ion-accessible adsorption sites (specific surface area and pore volume of 2637.4 m2 g-1 and 1.679 cm3 g-1) and anti-freezing EMIBF4-GBL electrolyte with high ion-conductivity (2.3 S cm-1 at -50 °C) can address this issue. Specifically, "H-bond breakage" in EMIBF4 ILs was proposed for the first time to understand the anti-freezing mechanism, as evidenced by Raman spectroscopy, 1H NMR spectroscopy, and density functional theory calculations. As a result, the combination of NMHC electrode with EMIBF4-GBL electrolyte enabled an impressive specific energy of 61 W h kg-1 at -50 °C, which was 10.7 times larger than that of commercial YP50. This work showed excellent electrode-electrolyte synergy and provides a new understanding of IL-based electrolytes for low-temperature energy storage.
UR - http://hdl.handle.net/10754/663535
UR - http://xlink.rsc.org/?DOI=D0TA02677H
UR - http://www.scopus.com/inward/record.url?scp=85085958071&partnerID=8YFLogxK
U2 - 10.1039/d0ta02677h
DO - 10.1039/d0ta02677h
M3 - Article
SN - 2050-7496
VL - 8
SP - 10386
EP - 10394
JO - Journal of Materials Chemistry A
JF - Journal of Materials Chemistry A
IS - 20
ER -